C M Y K

20 Marine Fisheries Information Service T&E Ser., No. 195, 2008

S.Rajapackiam, S. Mohan, P. Poovannan and G. SrinivasanMadras Research Centre of Central Marine Fisheries Research Institute, Chennai

On the rare landing of the deep water band fish Acanthocephalaabbriciata (Bleeker) at Chennai Fisheries Harbour

During September – November 2006, the deepwater band fish Acanthocephala abbriciata was

landed in large quantities by multiday trawlers atChennai fisheries harbour. Multiday trawlers areoperated 80-100 km off Chennai at a depth of 40-60m in the direction of northeast. A total of 620 kg, 350kg, and 200 kg were landed on 7-9-2006, 7-10-2006and 16-11-2006 respectively. There has been anearlier report on the landings of the Acanthocephalasp. in large quantities at Panayurkuppam, Chennai

from shallow waters in the month of August –September 1987. Fishermen opined that on 7.9.2006,the sea water turbidity increased and became blackin colour due to water current locally called“Vandalthanni”. At that time deep water fish like redbait and band fish were caught along with other fish.About 80 kg of red baits also landed on the sameday. The size range of band fish was 140 - 330 mmwith dominant mode at 230 - 239 mm. The weightrange was 12 - 66 g with a mean weight of 35.4 g.

Report on the Risso’s dolphin caught by gillnet at Chennai

S. Rajapackiam, S. Mohan and P. SelvanithiMadras Research Centre of Central Marine Fisheries Research Institute, Chennai

One Risso’s dolphin, Grampus griseus (G. Cuvier1812) was accidentally caught by a mechanised

gillnet along with tunas and rays at Chennai fisheries

harbour on 9-6-2005. The gill net was operated off Chennaiat distance of about 30-40 km. It was a male dolphinmeasuring 170 cm in total length and weighing 60 kg.

V.VenkatesanCentral Marine Fisheries Research Institute, Mandapam

Grading of sacred chanks along Ramanathapuram coast

Fishery of chanks along the Ramanathapuramcoast is formed by two varieties viz. Xancus

pyrum var acuta (Locally known as Jadhi) and Xancuspyrum var abtusa (Locally known as Patti) under thefamily Turbinellidae.

During 1980s, the chank fishery was under thecontrol of the Tamil Nadu state fisheries department.

The grading of chank was done by a gauge and themaximum shell diameter of chank was taken as ameans of grading for chank. The gauges used werewooden boards of 17.8 c.m. long, including handleand 11.5 c.m. wide, surrounding a circular brass-bound aperture. (Fig 1). Two sizes of gauge wereused. If it did not pass through the larger gauge (>75

21Grading of sacred chanks along Ramanathapuram coast

Table 2 Details of grading and price of chanks caught by

Shingi valai / Shangu madi / skin diving and trawl net during

2006.

Grade Gauge Price per Selling Price per

size piece price per piece to

:MSD at landing piece to finished

(mm) centre Shell craft product at

(Rs) industry Ramnad/

(Rs) Rameswaram

(Rs)

‘OO’- >110 600-650 800-700 1650 and

Class (450) (500) above

‘O’* 95-110 500-550 600-650 900-1300

Class (280) (350)

No. 1 90-95 400 450 800-1000

(220) (300)

No. II 85-90 350 400 400-600

(170) (200)

No. III 80-85 200 300 300-600

(140) (150)

No. IV 75-80 150 200 200-400

(80) (100)

No. V 70-75 80 100 150-350

(30) (50)

No. VI 65-70 40 60 150-350

(20) (30)

Air 60-65 20 30 100-270

(5) (10)

Kula 50-60 5 10 60-200

(2) (4)

Suthai >50 ... 1-1.50 75-125

Price of chanks caught by trawler is given in parenthesis

mm MSD), it was graded as a Class 1 Chank or Fullsized-I chank. If it passed through that but not throughthe smaller guage (64 mm MSD) it was graded as aClass 2 chank or Full sized II. Any shells which passedthrough the second gauge were graded asundersized chanks (>64 mm MSD) and confiscatedto discourage the divers from bringing immatureanimals ashore, those still alive were returned to thesea at the end of the day (Table 1). Any shells whichwere badly worm eaten were also confiscated. TheTamil Nadu chank fishery was a state monopoly theprice paid for FS-I and FS-II shells negotiatedannually. The Govt. sold the entire animal catch toWest Bengal Handicrafts Development Corporationlimited.

Table 1 Grading and price of chanks during 1980

Grade Gauge size Year : 1980

Price per pieceat landing centre

Class-I >85 mm MSD 3.50Class-II >75 mm to <85 mm 3.75

Class-III >64 mm to 75 mm --

During the 1994-95, Tamil Nadu Governmentremoved the entire control over the chank fisheriesexcept issuing licences to divers and boats for fishingchanks as there was decline in catches from thechank beds in previous years, the shell traders andmerchants of shell craft industry have introducedseveral grades in addition to above.

At present, the grading is also being carried outusing gauge of wooden boards as described abovebut without brass bound aperture and tripods stands.

Wooden boards are being held with left hand andshells are allowed to pass through the gauge by righthand. In some places, experienced merchants andmiddle men are using their hand as a gauge forgrading the chanks. When the shells are brought toshore, they are sorted again into several varietiesaccording to their size and quality, which largelydepends on the locality where they are caught, onthe gear in which they are caught and also thethickness of outer lip. These are auctioned tomiddlemen who supply the chank to the shell craftindustry or trader (Table 2).

Chanks are increasing caught in bottom trawlerand also in gear such as bottom set gillnets. The

chanks are vulnerable to over fishing because theyspend entire life on the sea bed. In the presentsystem, all sizes from juveniles to adult ones arecaught through non selective nature of fishing. Sothe earlier system of grading should be introducedonce again stringently in order to protect theundersized chanks.

The author is thankful to Dr. K.S. Mohamed,Head, Molluscan Fisheries Division, for critically goingthrough the manuscript and suggestingimprovements.